As the "Land Down Under," Australia is an island continent, so ancient visitors would have to arrived by sea, a long way from where humans first evolved in Africa. Migration to Australia would have required some remarkable ingenuity. Archaeologists have uncovered new evidence that could push the date of human habitation in Australia possibly as far as 80,000 years ago. The findings, that involve ancient tools and artifacts unearthed from Kakadu National Park in Australia's Northern Territory, suggest people crossed over from south Asia at a time that was cooler and wetter, with lower sea levels allowing easier sea crossings.

“People got here much earlier than we thought, which means of course they must also have left Africa much earlier to have traveled on their long journey through Asia and south-east Asia to Australia,” said the lead author, Associate Prof Chris Clarkson, from the University of Queensland. “It also means the time of overlap with the megafauna, for instance, is much longer than originally thought – maybe as much as 20,000 or 25,000 years. It puts to rest the idea that Aboriginal people wiped out the megafauna very quickly.”

Among the 11,000 artifacts collected as part of this study include ochre and reflective paint substances, as well as the oldest unbroken ground-edge stone axes in the world, by about 20,000 years, and the oldest known seed-grinding tools in Australia. Although there was some evidence that the artifacts could have shifted around over the years, dating methods gave a 95 percent chance that the uncovered artifacts were older than 70,000 years.

The discovery supports oral histories passed down through Australian aboriginal cultures for millennia. Many of that hinted that people have lived in Australia for much longer than scientists have previously believed. “We’d like to tell people we were here long enough – tell all the Balanda [non-Indigenous people] about the stories, that people were here a long time,” Mirarr traditional owner May Nango said.

More than 10,000 artifacts were uncovered in the “zone of first occupation”, including ochre and reflective paint substances, as well as the oldest unbroken ground-edge stone axes in the world, by about 20,000 years, and the oldest known seed-grinding tools in Australia.

“There’s a huge variety of these things spread over thousands of years. In some ways there are strong similarities with what happens at the very beginning, but there are also remarkable changes.”